Mitigating Return Drag and Regime Whipsaws in Sector Rotation: An Asymmetric Downside-Aware Nested Clustered Optimization Framework
In briefReducing Return Drag and Regime Switching in Sector Rotation: An Asymmetric Downside-Risk Nested Clustered Optimization Framework
SummaryThis paper addresses two weaknesses in sector rotation strategies: symmetric variance penalizes upside and downside equally, causing return drag, and Hidden Markov Model regimes switch too often, raising turnover. The authors propose Asym-Sticky-NCO, which combines a Bawa-Lindenberg downside semi-covariance matrix with a Gaussian HMM that has a persistence prior, applied to all 11 S&P 500 GICS sectors. In 65 out-of-sample months from August 2020 to December 2025, the framework reports a 13.41% CAGR and a 14.22% maximum drawdown, with regime switches cut from 16 to 4 and monthly turnover reduced from 60.78% to 30.48%.